Annulus filler

Abstract

An annulus filler is provided for mounting to a rotor disc of a gas turbine engine and for bridging the gap between two adjacent blades attached to the rotor disc. The annulus filler defines an airflow surface for air being drawn through the engine. The annulus filler has one or more primary connectors for connecting the annulus filler to the rotor disc, and for resisting, in use, centrifugal forces on the annulus filler. Each primary connector allows rotation of the annulus filler around the center line of the engine relative to the rotor disc at that primary connector. The annulus filler also has a secondary connector for connecting the annulus filler to the rotor disc and for resisting, in use, motion of the annulus filler relative to the rotor disc in a first axial direction. The secondary connector allows rotation of the annulus filler around the center line of the engine relative to the rotor disc at the secondary connector.

1. An annulus filler for mounting to a rotor disc of a gas turbine engine and for bridging a gap between two adjacent blades attached to the rotor disc, the annulus filler defining an airflow surface for air being drawn through the engine, the annulus filler comprising:
 one or more primary connectors for connecting the annulus filler to the rotor disc, and for resisting, in use, centrifugal forces on the annulus filler, each of the one or more primary connectors allowing rotation of the annulus filler around a centre line of the engine relative to the rotor disc at that primary connector; and 
 a secondary connector formed at an axial end of the annulus filler for connecting the annulus filler to the rotor disc and for resisting, in use, motion of the annulus filler relative to the rotor disc in a first axial direction, the secondary connector allowing rotation of the annulus filler around the centre line of the engine relative to the rotor disc at the secondary connector. 
 
     
     
       2. An annulus filler according to  claim 1 , wherein each of the one or more primary connectors further comprises a hook extending radially inwards for engagement with a correspondingly-shaped hook on the radially outer face of the rotor disc. 
     
     
       3. An annulus filler according to  claim 1 , wherein each of the one or more primary connectors further comprises a means to resist, in use, motion of the annulus filler relative to the rotor disc in an axial direction opposite the first axial direction. 
     
     
       4. An annulus filler according to  claim 1 , wherein the secondary connector further comprises a pin and slot coupling, the slot extending in a circumferential direction, and the pin extending through the slot in an axial direction and being movable along the slot to allow the rotation around the centre line at the secondary connector. 
     
     
       5. An annulus filler according to  claim 4 , wherein the slot is formed in the annulus filler. 
     
     
       6. An annulus filler according to  claim 4 , wherein the pin is provided by a fixing bolt which, in use, resists the motion of the annulus filler relative to the rotor disc in the first axial direction. 
     
     
       7. An annulus filler according to  claim 1 , wherein the secondary connector is configured to allow the rotation around the centre line at the secondary connector only within predetermined limits. 
     
     
       8. An annulus filler according to  claim 1  in which alignment means are provided to circumferentially align the filler relative to the rotor disc. 
     
     
       9. An annulus filler as claimed in  claim 8  in which the alignment means are datum surfaces on the filler and the rotor disc. 
     
     
       10. An annulus filler as claimed in  claim 8  in which the alignment means is a frangible pin which extends through the filler and the rotor disc. 
     
     
       11. An annulus filler according to  claim 1 , wherein the blades are fan blades.